The field of quantum reference frames, which recent progress is briefly presented in chap-
ter 1, is extremely relevant when it comes to understanding the deterioration of quantum states
and the evolution of quantum measurement instruments. However, to fully understand these
advances and to be able to bring an original contribution to this field, one must first understand
a number of concepts in physics and mathematics. These concepts are explained in chapter 2.
Since the deterioration of quantum states is very present when controlling useful states in quan-
tum computing, and since quantum computing attempts to control two-states systems, often
angular momenta, analyzing quantum reference frames proves to be relevant. Having s = 1 as 2
the smallest known angular momentum, and since its simplest state is the unpolarized state, the
study of a reference frame behavior that measures successively this type of angular momentums
is the first step to be taken (chapter 3). The most interesting questions concern the efficiency of
the reference frame, its longevity, and the optimization of these two quantities. The next step is
to consider polarized and general angular momentum states (chapter 4). This time, analyzing
the deterioration of the reference frame proves to be more complex, and can be examined in
an approximate manner by looking at the evolution of certain parameters given for a certain
class of states of reference frames. Furthermore, the existence of an interaction between the
reference frame and the angular momentum can affect the reference frame approximatively as
much as the measuring it does. It is this very interaction that is studied in chapter 5, but this
time, for s = 1 angular momenta. Comparing this interaction with the measurement shows very
clearly that the similarities between the two processes are a lot less visible than with s = 1 , and 2
even perhaps nonexistent. Therefore, the similarity does not seem to be general and appears to be accidental when it is significant.